As the elements in Period 3 are considered in order of increasing atomic number, there is a general decrease in:

- atomic radius

There is generally an increase in:

- atomic mass
- electronegativity
- first ionization energy

Atomic radius, because the number of electrons and protons increases by 1 each time you move right along period so there is greater electrostatic attraction (electrons are pulled to the nucleus more strongly) and there is no additional shielding to counteract this since the number of inner energy levels does not increase along a period.

Answered by BeckaH | 2024-06-10

In Period 3, atomic radius decreases while atomic mass, electronegativity, and first ionization energy generally increase due to the increase in effective nuclear charge. This is because as you move from left to right, protons are added to the nucleus, pulling electrons closer and affecting their properties. These trends showcase the underlying principles of atomic structure and electron behavior in chemistry.
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Answered by BeckaH | 2024-11-06